This is where my harsh house rule comes in: I don't want to do the endless mini game of ask the DM. So no INT checks like that. There are fewer things a hate more then a player that goofs around for three hours during a game, then at the start of the forth hour is like "yuck yuck, can I roll to find out the name of the town my character has been in for the last week?...yuck yuck yuck".
That... isn't quite what I was talking about.
It is perfectly reasonable IMO for something like a troll's issue with fire, or lycanthropes and silvered weapons, to be "common" knowledge in a fantasy world. However, such knowledge should not be perfect or always just assumed. For example, silvered weapons with werewolves might be distorted in the telling to include holy water--"Don't you know you need a silvered weapon, dipped in holy water, and blessed by a priest!"--instead of just, "No, a silvered weapon alone would do it... I don't know where you got the rest of that from."
Not every PC will know the "truth" or facts when it comes to such things. Some might not know them at all, others have it incorrect, and other know the truth of it. That is what I am talking about and why a simple DC 10 Intelligence check suffices in most cases IME.
Without this, how do you know what "real world" knowledge a PC has in their own world. I mean, the characters live IN their world, they should know certain things, right??
Now, what you
thought I meant is very annoying and frustrating, I agree. And I don't jive for that, either. If a player can't remember details, write them down, otherwise your PC is going to embarass themselves when the call the town "Merrydown" when it fact is was "Thusselton" or something.